Investment funds rebuilt copper exposure decisively in the week to 25 September, adding more than 4,100 longs while simultaneously covering shorts. Aluminium and lead moved in the same bullish direction. Zinc did not: its net long fell for a third consecutive week as funds added almost 4,000 shorts, leaving the complex without a common direction for the first time in a month.
TL;DR
- Copper was the clearest bullish move. Funds added 4,129.30 longs and covered 609.28 shorts, lifting net length by 4,738.58 lots to +44,557.28.
- The copper move reverses four consecutive weeks of declining conviction. Net length had fallen from +48,315.65 on 28 August to +39,818.70 on 18 September before the latest rebound.
- Aluminium strengthened too. Funds added 3,710.25 longs against 1,358.27 new shorts, increasing net length by 2,351.98 lots to +146,411.54.
- Lead remains the only net-short metal, but the long book has expanded sharply. Longs reached 46,299.90 lots, up 38.4% from 33,441.26 on 11 September, while the net short contracted by 3,192.68 lots this week to −21,946.20.
- Zinc moved in the opposite direction. Shorts increased 3,949.65 lots against 1,608.44 new longs, reducing net length by 2,341.21 lots to +51,392.89.
- Investment Fund zinc positions on the long and short sides sum to 51.87% of open interest, the highest combined figure among the six contracts. This is a gross positioning comparison rather than a share of the market and can in principle exceed 100%.
- Nickel remained defensive, with shorts growing faster than longs and net length falling another 568.33 lots to +12,819.83.
- Tin barely changed. Short covering outweighed modest long liquidation, increasing net length by 73 lots to +1,993.
- The complex has split. Copper, aluminium and lead became more bullish; zinc and nickel became less bullish; tin was effectively unchanged.
- Unlike the previous reporting week, the 25 September positions and LME-reported weekly changes reconcile exactly with the preserved 18 September vintage across all six metals. No restatement is evident in this week's files.
Investment-Fund Positioning Board
| Metal | 25 Sep long | 25 Sep short | Net | Δ longs | Δ shorts | Δ net |
|---|---|---|---|---|---|---|
| Copper | 69,599.77 | 25,042.49 | +44,557.28 | +4,129.30 | −609.28 | +4,738.58 |
| Aluminium | 195,185.66 | 48,774.12 | +146,411.54 | +3,710.25 | +1,358.27 | +2,351.98 |
| Zinc | 125,512.79 | 74,119.90 | +51,392.89 | +1,608.44 | +3,949.65 | −2,341.21 |
| Nickel | 51,048.45 | 38,228.62 | +12,819.83 | +748.59 | +1,316.92 | −568.33 |
| Tin | 2,614 | 621 | +1,993 | −26 | −99 | +73 |
| Lead | 46,299.90 | 68,246.10 | −21,946.20 | +4,352.89 | +1,160.21 | +3,192.68 |
Source: London Metal Exchange MiFID II Weekly COTR reports, positions as at 25 September 2026, published 29 September 2026. Weekly changes are those reported by the LME and reconcile with the current positions.
The board is materially different from 18 September. Last week five of the six metals became less bullish or more bearish and every short book grew. This week there is no common direction. Copper, aluminium and lead strengthened; zinc and nickel weakened; tin was essentially unchanged.
The mechanics matter as much as the net figures. Copper's improvement came overwhelmingly from new longs, supplemented by short covering. Lead attracted substantial new long exposure even though funds remain net short. Aluminium also added considerably more longs than shorts. Zinc did the reverse: both sides expanded, but the short book grew more than twice as quickly as the long side.
In tonnage terms, copper's +4,738.58-lot net move represents approximately 118,465 tonnes, aluminium's +2,351.98 represents 58,800 tonnes and lead's 3,192.68-lot improvement represents 79,817 tonnes. Zinc's reduction equates to approximately 58,530 tonnes, nickel's −568.33 lots to 3,410 tonnes and tin's +73 lots to just 365 tonnes. Lot sizes differ by metal and positions cannot be aggregated across the complex.
Market Share and Participation
The open-interest data provide another way to compare the scale of Investment Fund positioning across the six contracts, but they require careful interpretation.
| Metal | IF long % OI | IF short % OI | Long + short % OI | IF holders |
|---|---|---|---|---|
| Copper | 16.67% | 5.99% | 22.66% | 234 |
| Aluminium | 21.84% | 5.46% | 27.30% | 306 |
| Zinc | 32.61% | 19.26% | 51.87% | 301 |
| Nickel | 15.97% | 11.96% | 27.93% | 280 |
| Tin | 11.05% | 2.62% | 13.67% | 96 |
| Lead | 17.34% | 25.56% | 42.90% | 239 |
The third column simply adds Investment Fund long and short percentages of open interest. It is a gross positioning comparison, not a conventional market-share measure. Because long and short positions are counted separately, the figure can in principle exceed 100% of open interest.
Zinc stands out. Investment Fund longs equal 32.61% of open interest and shorts 19.26%; adding the two sides produces 51.87%. There are 301 Investment Fund position holders. The latest increase in zinc shorts is therefore occurring in a contract where funds have substantial positions on both sides, but the 51.87% figure should not be interpreted as funds controlling that proportion of the market.
Lead is the other contract with unusually large fund positioning relative to open interest. Investment Fund shorts equal 25.56% of OI, the largest short percentage among the six metals, against 17.34% long, and the two sides sum to 42.90%. That makes this week's long accumulation particularly notable: funds remain structurally net bearish, but bullish exposure is building alongside a large existing short book.
Aluminium has the broadest Investment Fund participation by holder count, with 306, marginally ahead of zinc's 301. Its long and short positions equal 21.84% and 5.46% of open interest respectively. Nickel has 280 holders, with positions equivalent to 15.97% of OI long and 11.96% short.
Copper has 234 Investment Fund position holders, with long positions equal to 16.67% of OI and shorts 5.99%. The bullish turn therefore comes from a substantial participant base without the unusually large positioning relative to OI visible in zinc or lead. Tin remains the smallest fund market in both senses: 96 Investment Fund holders, with longs equal to 11.05% of OI and shorts 2.62%.
Copper: Bulls Return
Copper is the headline because the direction and composition changed together.
Funds added 4,129.30 longs to 69,599.77 while covering 609.28 shorts to 25,042.49. Net length consequently jumped 4,738.58 lots to +44,557.28. At a 25-tonne contract size, that is an increase of approximately 118,465 tonnes of net exposure in one reporting week.
The sequence gives the move more significance. Copper net length stood at +48,315.65 on 28 August, +45,817.21 on 4 September, +40,773.38 on 11 September and +39,818.70 on 18 September. Over those four weeks, net bullish exposure fell by 8,496.95 lots, or 17.6%. The latest week's 4,738.58-lot increase has recovered 55.8% of that decline.
The mechanism has changed too. The move to 11 September was dominated by long liquidation. The deterioration to 18 September came instead from new shorts. To 25 September, funds did the opposite on both sides: longs rose substantially and shorts fell.
That is the cleanest bullish positioning signal copper has produced in several reporting weeks. It does not establish why funds bought, and COTR data should not be used to infer motivation, but it does establish that the improvement was driven principally by new long exposure rather than a mechanical change in the short book.
Lead: The Short Starts to Unwind
Lead produced the second-largest improvement in net positioning, rising 3,192.68 lots to −21,946.20.
More important is what is happening inside the gross book. Investment Fund longs reached 46,299.90 lots, up from 41,947.01 on 18 September and 33,441.26 on 11 September. The long book has therefore expanded by 12,858.64 lots, or 38.4%, in a fortnight.
This week's increase was particularly strong. Funds added 4,352.89 longs while adding only 1,160.21 shorts, taking the short book to 68,246.10. Unlike the previous week, when both sides expanded aggressively and the net improvement was marginal, the latest gross expansion was distinctly skewed towards the bullish side.
The OI data put that move in context. Investment Fund shorts still equal 25.56% of lead open interest, compared with 17.34% for longs. Lead therefore remains the only net-short metal in the six-contract group and has the largest Investment Fund short percentage of OI.
The significance is the change at the margin. A 38.4% expansion of the long book in two weeks is a stronger signal than the latest reduction in the net short alone, and it is happening in the contract where funds hold their largest bearish position relative to open interest.
Aluminium: Longs Rebuild
Aluminium also moved back towards the bullish side. Funds added 3,710.25 longs to 195,185.66 and 1,358.27 shorts to 48,774.12, increasing net length by 2,351.98 lots to +146,411.54, equivalent to approximately 3.66 million tonnes.
This is not a return to the unusual early-September configuration in which aluminium's net position increased despite gross longs falling. This time the long book itself expanded, and did so substantially faster than the short side. Investment Funds account for long exposure equal to 21.84% of aluminium OI against just 5.46% short, while its 306 Investment Fund holders are the largest participant count among the six metals.
Aluminium nonetheless remains by a wide margin the largest net long in the complex, and the short book has grown in each of the last two reporting weeks even as longs have rebuilt. The structural feature that made it distinctive — an almost absent bear side — continues to erode.
Zinc: The Short Build Continues
Zinc is the clearest counterpoint to copper.
Funds added 1,608.44 longs, taking the long book to 125,512.79, but added 3,949.65 shorts to 74,119.90. Net length consequently fell another 2,341.21 lots to +51,392.89.
The direction has persisted. In the preserved 4 September COTR vintage, zinc Investment Fund net length was +62,651.95 lots. By 25 September it had fallen 11,259.06 lots, or 18.0%. The 4 September figure comes from Bloodstone Research's retained LME weekly file and did not appear in the two subsequent published positioning articles.
This is not straightforward long liquidation. The latest report shows the long book expanding. The deterioration came because funds built bearish exposure more than twice as quickly, which is the same mechanism recorded in each of the previous two weeks.
Investment Fund longs now equal 32.61% of zinc open interest and shorts 19.26%. The two sides sum to 51.87% of OI, the highest combined long-plus-short percentage among the six contracts. That does not mean Investment Funds have a 51.87% market share: the calculation counts long and short positions separately and can theoretically exceed 100%. It does show that substantial Investment Fund positions exist on both sides of zinc, which makes a sustained short build there more consequential than the equivalent in a contract where funds are lightly represented.
Nickel and Tin
Nickel remained defensive. Funds added 748.59 longs but 1,316.92 shorts, reducing net length by another 568.33 lots to +12,819.83. The move is smaller than the previous week's 2,898.58-lot reduction, but the mechanism is similar: funds are still adding exposure on both sides while the bearish side grows faster. Investment Fund positions equal 15.97% of OI long and 11.96% short, with 280 holders, making nickel the most balanced book among the net-long metals.
Tin barely moved. Funds removed 26 longs and covered 99 shorts, lifting net length by 73 lots to +1,993. Investment Fund exposure is comparatively light at 11.05% of OI long and 2.62% short, with only 96 holders. At a five-tonne lot, the weekly net change represents just 365 tonnes, and the appropriate interpretation is essentially neutral.
The Metals Book Splits
Last week's defining feature was unusually broad short building. Every one of the six metals added shorts and five recorded lower net length. That pattern has broken.
Copper is the clearest reversal: new longs arrived and shorts were covered. Aluminium added longs substantially faster than shorts. Lead remains net bearish but recorded a sizeable bullish skew in its new gross exposure. Zinc and nickel moved in the opposite direction, with short books expanding faster than longs, while tin barely changed.
The open-interest data sharpen that distinction. Zinc and lead are the two contracts where Investment Fund positions are largest relative to open interest, at 51.87% and 42.90% on a combined long-plus-short basis, yet their positioning structures are moving in opposite directions. Zinc remains net long but is becoming less bullish as shorts accumulate. Lead remains net short but is becoming less bearish as longs build. The two contracts where funds matter most are therefore converging on each other from opposite ends.
Copper has regained a substantial part of the positioning lost during September, and done so through the composition that carries the most information: new longs rather than covered shorts. Whether that was the start of a durable change or a one-week reversal around quarter-end is what the next vintage will establish.
Outlook
Base case: Positioning remains differentiated rather than returning immediately to the broad short-building pattern seen to 18 September. Copper's rebuilt long book holds, while zinc's short accumulation continues at a slower pace.
Upside risk: Copper's long accumulation continues, aluminium's short book stabilises while longs expand, and lead's net short contracts further. A simultaneous reduction in zinc shorts would materially broaden the bullish positioning signal.
Downside risk: Copper's latest rebuild proves temporary and the broad short accumulation seen earlier in September resumes, with aluminium's thin bear side continuing to fill out from the largest net long in the complex.
What would change the view: Another substantial week of copper long accumulation would turn a one-week reversal into a developing trend. In zinc, a contraction in the gross short book would end a three-week sequence. In lead, continued long accumulation would matter more than a simple reduction in shorts.
Key Risks
Point-in-time data. The COTR files capture positions as at 25 September and do not reveal the sequence of transactions within the reporting week.
Gross and net signals differ. Zinc added longs while becoming less bullish because its short book expanded much faster. Lead remains net short despite a strongly bullish weekly flow.
Open-interest percentages require care. The long-plus-short figure counts both sides separately. It is a gross positioning comparison, not market share, and can in principle exceed 100%.
Lot sizes differ. Aluminium, copper, zinc and lead use 25-tonne lots, nickel six tonnes and tin five. Raw lot positions cannot be aggregated across metals.
Small bases exaggerate. Tin's weekly net change of 73 lots represents 365 tonnes across 96 position holders.
Positioning is not a forecast. The COTR records what funds did, not what they concluded, and a single week's reversal around quarter-end may not persist.
Quarter-end effects. The 25 September reporting period sits close to quarter-end, making it important to establish whether the latest positioning changes hold into October.
Intelligence Monitoring Points
- Copper gross longs after the 4,129.30-lot weekly increase, and whether the rebuild continues into the first October vintage.
- Copper shorts after their contraction to 25,042.49 lots.
- Zinc's 74,119.90-lot short book, after three consecutive weeks of accumulation.
- Aluminium's short book, which has grown in each of the last two weeks from an unusually thin base.
- Lead longs after the 38.4% fortnightly expansion, and whether the 25.56% short share of OI begins to contract.
- Nickel's balance, at 15.97% of OI long against 11.96% short, the most evenly positioned of the net-long metals.
- Whether the complex remains divided or returns to a common positioning direction after quarter-end.
FAQ
What was the biggest positioning change this week? Copper. Net length increased 4,738.58 lots to +44,557.28 as funds added 4,129.30 longs and covered 609.28 shorts. The composition makes this a stronger bullish signal than an increase driven primarily by short covering.
Has copper recovered all of September's positioning decline? No. Net length was +48,315.65 on 28 August and fell to +39,818.70 by 18 September. The latest rebound to +44,557.28 restores 55.8% of that decline.
What is changing in lead? Funds remain net short by 21,946.20 lots, but the long book has risen from 33,441.26 on 11 September to 46,299.90 on 25 September, an increase of 38.4% in two weeks. Lead remains the most bearish net position of the six, but the composition is changing.
Why does zinc matter? Funds have added shorts for three consecutive weeks, taking net length down 18.0% from the preserved 4 September vintage, and they hold larger positions relative to open interest in zinc than in any other contract.
Do Investment Funds account for 51.87% of the zinc market? No. Investment Fund long positions equal 32.61% of OI and shorts 19.26%. Adding them produces 51.87%, but that is a gross positioning comparison rather than market share. Long and short positions are counted separately, so the measure can theoretically exceed 100%.
Did any metal's figures require restatement? No. All six reconcile exactly with the preserved 18 September vintage, unlike the previous week, when tin's reported change did not match the published prior position.
Data and source note: London Metal Exchange MiFID II Weekly COTR reports for aluminium, copper, zinc, nickel, lead and tin, positions as at 25 September 2026 and published 29 September 2026. Position figures, weekly changes, open-interest percentages and holder counts refer to the LME Investment Funds category, non-risk-reducing. Weekly changes are those printed by the LME and reconcile exactly with the current positions and Bloodstone Research's preserved 18 September vintage across all six metals; no restatement is evident in the 25 September files. Historical comparisons use the relevant preserved weekly LME vintage, including zinc's +62,651.95-lot net position from the 4 September file. The long-plus-short percentage of open interest is calculated by Bloodstone Research solely as a gross positioning comparison. Because long and short positions are counted separately, it is not market share and can in principle exceed 100% of open interest. Tonnage equivalents use contract sizes of 25 tonnes for aluminium, copper, zinc and lead, six tonnes for nickel and five tonnes for tin. Lot positions cannot be aggregated across metals. COTR data are point-in-time positions and do not describe activity after the reporting date.
Sources
- London Metal Exchange — Commitments of Traders
- London Metal Exchange — MiFID II Weekly COTR reports, report date 29 September 2026, positions as at 25 September 2026: aluminium, copper, zinc, nickel, tin and lead
- Bloodstone Research — LME Positioning Intelligence, 24 September 2026
This document is published by Bloodstone Research for informational and institutional research purposes only. It does not constitute investment advice, an investment recommendation, an offer or solicitation to buy or sell any financial instrument, commodity or security, or a forecast of future performance. Market conditions and data may change without notice. Readers should conduct their own analysis and, where appropriate, seek independent professional advice before making investment decisions. For institutional enquiries contact research@bloodstonecapital.co.uk.